| Acronym | Definition |
|---|
| ATD | Anthropomorphic Test Dummy |
| ATD | Antidepressants |
| ATD | Attention to Detail |
| ATD | Advanced Technology Demonstration |
| AtD | Achieving the Dream |
| ATD | Atmospheric Technology Division (US National Center for Atmospheric Research) |
| ATD | Advanced Technology Development |
| ATD | Apprenticeship and Training Division |
| ATD | Actual Time of Departure |
| ATD | Asynchronous Time Division |
| ATD | Against the Day (Glasgow band) |
| ATD | Anthropomorphic Test Device |
| ATD | Assistant Technical Director |
| ATD | Automatic Target Detection |
| ATD | Arrival Time Difference |
| ATD | Aircrew Training Device |
| ATD | Amused to Death (Roger Waters album) |
| ATD | Applied Technology Division |
| ATD | Agree to Disagree (internet slang) |
| ATD | Auto Trim Design (Fairbanks, AK) |
| ATD | Acquired Toilet Disease (fictitious disease) |
| ATD | Address Transition Detection (circuit in asynchronous memory) |
| ATD | Aid to the Totally Disabled |
| ATD | Automated Test Designer (software; @YourSide Consulting) |
| ATD | Attitude Determination |
| ATD | Along Track Distance (aviation) |
| ATD | Automated Thermal Desorber (gas chromatography analysis column type) |
| ATD | Aerospace Technology Division (Library of Congress; formerly Aerospace Information Division) |
| ATD | Associação Terras Dentro |
| ATD | Adjustable Time Delay |
| ATD | Aided Target Detection |
| ATD | Available to Deploy |
| ATD | Abrams Travel Data Services |
| ATD | Antitheft Device |
| ATD | Authorized Terminal Distributor |
| ATD | Anti-Tank Ditch |
| ATD | Active Threat Defense (Cisco) |
| ATD | Alliance Tchadienne pour la Démocratie et le Développement (Chadian Alliance for Democracy and Development, Chad) |
| ATD | Automated Tactical Data Link |
| ATD | Advanced Technologies Demonstration (ARPA/Bell Atlantic) |
| ATD | Assistant Train Dispatcher (NYC Transit Authority) |
| ATD | Acceptance and Takeover Date |
| ATD | Actuals To Date |
| ATD | Astronaut Translation Device |
| ATD | Association of Telecommunications Dealers |
| ATD | Air and Toxics Division |
| ATD | Automatic Tube Dispenser |
| ATD | Aero Tech Designs (Coraopolis, PA) |
| ATD | Audio Tone Detector |
| ATD | Adaptive Threshold Detector |
| ATD | Automated Training Device |
| ATD | Aviation Test Directorate |
| ATD | Automatic Tone Detector (Sprint) |
| ATD | Air Technician Detachment |
| ATD | Assignment and Transmittal Document (SAIC stock) |
| ATD | Automatic Target Designation |
| ATD | AUTOVON Tandem Digital |
| ATD | ATM Test Development |
| ATD | Anti Theft Discount (insurance) |
| ATD | Amphibische Technische Dienst (Dutch) |
| ATD | Average to Date |
| ATD | All Terrain Drilling Pty Ltd (Australia) |
| ATD | Asset Transfer Date |